In the field of data processing, the sorting of documents such as bank checks requires numerous operations and routing of the checks past various devices for separating the checks and moving them into pockets or bins according to a desired format. The sorting process may include arranging a number of documents into a sequence as determined by information recorded on the document and sensed by readers which are adjacent the flow or path of the documents.
While the number of sorting pockets or bins which make up part of a sorting machine may vary from a pair of pockets to as many as twenty or more, it is desirable to simplify the sorting operation and to reduce the number of steps or instructions which are utilized in the operation. In this manner, the programmed format or instruction is easier to implement into the operation and to follow through in the performing of the processing operation.
Representative prior art in document sorting apparatus is disclosed in U.S. Pat. No. 3,304,080, issued to B. J. Greenblott et al on Feb. 14, 1967, wherein documents are sorted by merging according to their ascending or descending sequential value and using pairs of groups of document magazines operable with document transport belts. Control means operates to move the document having the lowest value and comparing it with previous values until a break in sequence occurs. A new magazine in the group is selected and the comparing process is repeated until all documents compared in the first group are lower than the last document with continuation of the process until a single sequence results.
U.S. Pat. No. 3,324,459, issued to R. L. Woolfolk on June 6, 1967, discloses program changing in data processing wherein a method and apparatus use means for changing the contents of a memory storing the sorting program of an apparatus for sorting documents. A program change document is used and fed to the sorting apparatus wherein the change document has recorded thereon the program change information along with a special symbol and the sorting apparatus detects the special symbol and changes the information stored in its memory in accordance with the program change information recorded on the document.
U.S. Pat. No. 3,380,029, issued to M. A. Goetz on Apr. 23, 1968, shows a sorting system employing a computer and a plurality of magnetic tape units and a control system made up of three control signal loops. A first loop develops sets of data signal combinations into sorted strings of a first order and a second loop performs a merge on the first order strings except for one string and then writes a string of the next higher order on a remaining tape unit. A third loop directs the alternating operation of the first and the second control loops.
U.S. Pat. No. 3,587,057, issued to P. N. Armstrong on June 22, 1971, shows a data sorting system with control means to sort records into an ascending or descending progression. The system sorts a file of records which contains more records than the capacity of the system by repeated circulation of the file. Each record has an identifying number and sorting is accomplished by a representation of an increasing sequence of numbers wherein each succssive record is compared with previous records.
U.S. Pat. No. 3,662,402, issued to K. L. Bond et al. on May 9, 1972, discloses a data sort method utilizing finite difference tables wherein a sequence of information items, each of which has an assigned numerical value, is sorted to obtain a list arranged in order of ascending or descending magnitude. This is accomplished by generating a difference table for the sequence and then interchanging various items of the sequence depending on the entries of the difference table. A fast memory is used to sort the information items in a short time and use a minimum of the access memory by means of a mathematical technique to move and sort the items in the fast access memory.